Polymorphis of a known thiophenecarboxylic acid dodecahydrocyclopenta (a) phenanthrenyl ester

ABSTRACT

Polymorphic crystal forms of 3-methylthiophene-2-carboxylic acid (6S,9R,10S,11S,13S,16R, 17R)-9-chloro-6-fluoro-11-hydroxy-17-methoxycarbonyl-10,13,16-trimethyl-3-oxo-6,7,8,9,10, 11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-17-yl ester. The crystal forms possess anti-inflammatory activity and have very good stability. Methods for preparing the crystal forms are also described.

This invention relates to new polymorphic crystal forms of a compound offormula I and methods for preparing them.

The compound of formula I, namely 3-methylthiophene-2-carboxylic acid(6S,9R,10S,11S,13S,16R,17R)-9-chloro-6-fluoro-11-hydroxy-17-methoxycarbonyl-10,13,16-trimethyl-3-oxo-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-17-ylester, possesses a high anti-inflammatory activity. This activity can bedemonstrated by its inhibition of TNF-alpha synthesis and release in ahuman macrophage cell line and by its inhibition of inflammatoryconditions, particularly in the airways, e.g. inhibition of eosinophilactivation, in animal models, e.g. mouse or rat models of airwaysinflammation, for example as described by Szarka et al, J. Immunol.Methods (1997) 202:49-57; Renzi et al, Am. Rev. Respir. Dis. (1993)148:932-939; Tsuyuki et al., J. Clin. Invest. (1995) 96:2924-2931; andCernadas et al (1999) Am. J. Respir. Cell Mol. Biol. 20:1-8.

This compound has been investigated for use as a pharmaceutical. Theexistence of various crystallisation polymorphic forms of the compoundhas been explored in order to determine the most appropriate form of thecompound for the proposed use.

Novel crystal forms of the compound of formula I have now been isolated.Some of these novel crystal forms have very good stability, facilitatingtheir use in the preparation of pharmaceutical dosage forms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an X-ray powder diffraction pattern of Crystal form A of thecompound of formula I,

FIG. 2 is an X-ray powder diffraction pattern of Crystal from B of thecompound of formula I.

Accordingly, the present invention provides in one aspect a compound offormula I

in a crystal form A that has a melting point, by Differential ScanningCalorimetry, of about 264° C. with simultaneous decomposition, at aheating rate of 20° C./min and the following characteristic diffractionlines (2θ in angular degrees±0.2°) in the X-ray diffraction patternthereof: 3.6°, 7.3°, 13.4°, 14.6°, 18.3°, 22.0°, 25.8°, 25.9°, 29.5°; orin a crystal form B that has a melting point, by Differential ScanningCalorimetry, of about 270° C. with simultaneous decomposition, at aheating rate of 20° C./min and the following characteristic diffractionlines (2θ in angular degrees±0.2°) in the X-ray diffraction patternthereof: 7.2°, 9.3°, 12.0°, 12.8°, 13.1°, 14.5°, 17.4°, 20.4°, 23.2° and25.8°.

Crystal form A may be prepared by crystallising the compound of formulaI from a solution thereof in an organic solvent such as isopropanol,ethyl acetate, n-butanol, hexane, heptane, tert-butylmethylether,toluene or tetrahydrofuran, for example by equilibrating the compound inthat solvent over 24 hours at 25° C., or analogously such as hereinafterdescribed in Example 1. The crystallisation may be induced by, forexample, cooling a supersaturated solution of the compound of formula Iin the solvent, or by adding to the solution of the compound of formulaI a solvent in which the compound of formula I is less soluble. Thestarting solution of the compound of formula I may be at ambient orelevated (up to reflux) temperature.

Crystal form B may be prepared by crystallising the compound of formulaI from a solution thereof in a polar organic solvent such as ethanol,methanol or methylene chloride, for example by equilibrating thecompound in that solvent over 24 hours at 25° C., or analogously such ashereinafter described in Example 2. The crystallisation may be inducedby, for example, cooling a supersaturated solution of the compound offormula I in the polar solvent, or by adding to the solution of thecompound of formula I a polar solvent in which the compound of formula Iis less soluble. The starting solution of the compound of formula I maybe at ambient or elevated (up to reflux) temperature.

For the preparation of each of the crystal forms, working up may becarried out generally using known procedures for the separation of thecrystallisate from the mother liquor, for example by filtration, with orwithout the assistance of pressure and/or vacuum, or by centrifugation,and subsequent drying of the crystallisate.

In the presence of ethanol crystal form A converts to crystal form B. Inthe presence of isopropanol crystal form B converts to crystal form A.

The crystal forms can be distinguished in particular by their X-raypowder diagrams. X-ray diagrams taken with a diffractometer and usingCu-Kα₁-radiation are preferably used to characterise solids of organiccompounds. X-ray powder diffraction diagrams are particularly useful todetermine the crystal form or modification of the compound of formula I.The use of such diagrams is described in the accompanying Examples.

Crystal form A appears to be more thermodynamically stable than crystalform B in the solid state. However, in suspension with solvents thestability is solvent dependent.

The compound of formula I may be prepared in accordance with the methodgiven in Example 26 of international patent application WO 02/00679.

Given its anti-inflammatory activity, the compound of formula I incrystal form A or B is useful in the treatment of inflammatoryconditions, particularly inflammatory or obstructive airways diseases.Treatment in accordance with the invention may be symptomatic orprophylactic.

Inflammatory or obstructive airways diseases to which the presentinvention is applicable include asthma of whatever type or genesisincluding both intrinsic (non-allergic) asthma and extrinsic (allergic)asthma, mild asthma, moderate asthma, severe asthma, bronchitic asthma,exercise-induced asthma, occupational asthma and asthma inducedfollowing bacterial infection. Treatment of asthma is also to beunderstood as embracing treatment of subjects, e.g. of less than 4 or 5years of age, exhibiting wheezing symptoms and diagnosed or diagnosableas “wheezy infants”, an established patient category of major medicalconcern and now often identified as incipient or early-phase asthmatics.(For convenience this particular asthmatic condition is referred to as“wheezy-infant syndrome”.) Prophylactic efficacy in the treatment ofasthma will be evidenced by reduced frequency or severity of symptomaticattack, e.g. of acute asthmatic or bronchoconstrictor attack,improvement in lung function or improved airways hyperreactivity. It mayfurther be evidenced by reduced requirement for other, symptomatictherapy, i.e. therapy for or intended to restrict or abort symptomaticattack when it occurs, for example anti-inflammatory (e.g.corticosteroid) or bronchodilatory. Prophylactic benefit in asthma mayin particular be apparent in subjects prone to “morning dipping”.“Morning dipping” is a recognised asthmatic syndrome, common to asubstantial percentage of asthmatics and characterised by asthma attack,e.g. between the hours of about 4 to 6 am, i.e. at a time normallysubstantially distant from any previously administered symptomaticasthma therapy.

Other inflammatory or obstructive airways diseases and conditions towhich the present invention is applicable include acute lung injury(ALI), adult respiratory distress syndrome (ARDS), chronic obstructivepulmonary, airways or lung disease (COPD, COAD or COLD), includingchronic bronchitis or dyspnea associated therewith, emphysema, as wellas exacerbation of airways hyperreactivity consequent to other drugtherapy, in particular other inhaled drug therapy. The invention is alsoapplicable to the treatment of bronchitis of whatever type or genesisincluding, e.g., acute, arachidic, catarrhal, croupus, chronic orphthinoid bronchitis. Further inflammatory or obstructive airwaysdiseases to which the present invention is applicable includepneumoconiosis (an inflammatory, commonly occupational, disease of thelungs, frequently accompanied by airways obstruction, whether chronic oracute, and occasioned by repeated inhalation of dusts) of whatever typeor genesis, including, for example, aluminosis, anthracosis, asbestosis,chalicosis, ptilosis, siderosis, silicosis, tabacosis and byssinosis.

Having regard to its anti-inflammatory activity, in particular inrelation to inhibition of eosinophil activation, the compound of formulaI in crystal form A or B is also useful in the treatment of eosinophilrelated disorders, e.g. eosinophilia, in particular eosinophil relateddisorders of the airways (e.g. involving morbid eosinophilicinfiltration of pulmonary tissues) including hypereosinophilia as iteffects the airways and/or lungs as well as, for example,eosinophil-related disorders of the airways consequential or concomitantto Löffler's syndrome, eosinophilic pneumonia, parasitic (in particularmetazoan) infestation (including tropical eosinophilia),bronchopulmonary aspergillosis, polyarteritis nodosa (includingChurg-Strauss syndrome), eosinophilic granuloma and eosinophil-relateddisorders affecting the airways occasioned by drug-reaction.

The compound of formula I in crystal form A or B is also useful in thetreatment of inflammatory conditions of the skin, for example psoriasis,contact dermatitis, atopic dermatitis, alopecia greata, erythemamultiforma, dermatitis herpetiformis, scleroderma, vitiligo,hypersensitivity angiitis, urticaria, bullous pemphigoid, lupuserythematosus, pemphisus, epidermolysis bullosa acquisita, and otherinflammatory conditions of the skin.

The compound of formula I in crystal form A or B may also be used forthe treatment of other diseases or conditions, in particular diseases orconditions having an inflammatory component, for example, treatment ofdiseases and conditions of the eye such as conjunctivitis,keratoconjunctivitis sicca, and vernal conjunctivitis, diseasesaffecting the nose including allergic rhinitis, diseases of the jointssuch as rheumatoid arthritis and inflammatory bowel disease such asulcerative colitis and Crohn's disease.

The compound of formula I in crystal form A or B is also useful as aco-therapeutic agent for use in conjunction with other drug substancesfor treatment of airways diseases, particularly bronchodilatory oranti-inflammatory drug substances, particularly in the treatment ofobstructive or inflammatory airways diseases such as those mentionedhereinbefore, for example as potentiators of therapeutic activity ofsuch drugs or as a means of reducing required dosaging or potential sideeffects of such drugs. The compound of formula I in crystal form A or Bmay be mixed with the other drug in a fixed pharmaceutical compositionor it may be administered separately, before, simultaneously with orafter the other drug.

Such anti-inflammatory drugs include steroids, in particularglucocorticosteroids such as budesonide, beclamethasone dipropionate,fluticasone propionate, ciclesonide or mometasone furoate and compoundsdescribed in WO 0200679, WO 0288167, WO 0212266 and WO 02100879; LTB4antagonists such as those described in U.S. Pat. No. 5,451,700; LTB4antagonists such as those described in U.S. Pat. No. 5,451,700; LTD4antagonists such as montelukast and zafirlukast; dopamine receptoragonists such as cabergoline, bromocriptine, ropinirole and4-hydroxy-7-[2-[[2-[[3-(2-phenylethoxy)-propyl]sulfonyl]ethyl]amino]ethyl]-2(3H)-benzothiazoloneand pharmaceutically acceptable salts thereof (the hydrochloride beingVIOZAN® (sibenadet HCl)—AstraZeneca); PDE4 inhibitors such as ARIFLO®(cilomilast) (GlaxoSmith Kline), Roflumilast (Byk Gulden), V-11294A(Napp), BAY19-8004 (Bayer), SCH-351591 (Schering-Plough), Arofylline(Almirall Prodesfarma), PD189659 (Parke-Davis), AWD-12-281 (AstaMedica), CDC-801 (Celgene) and KW-4490 (Kyowa Hakko Kogyo); A2a agonistssuch as those described in EP 1052264, EP 1241176, WO 0023457, WO0077018, WO 0123399, WO 0160835, WO 0194368, WO 0200676, WO 0222630, WO0296462, WO 0127130, WO 0127131, WO 9602543, WO 9602553, WO 9828319, WO9924449, WO 9924450, WO 9924451, WO 9938877, WO 9941267, WO 9967263, WO9967264, WO 9967265, WO 9967266, WO 9417090, EP 409595A2 and WO 0078774;and A2b antagonists such as those described in WO 02/42298.

Such bronchodilatory drugs include anticholinergic or antimuscarinicagents, such as those described in EP 424021, U.S. Pat. No. 5,171,744(Pfizer) and WO 01/04118 (Almirall Prodesfarma) and but in particularipratropium bromide, oxitropium bromide and tiotropium bromide, andbeta-2 adrenoceptor agonists such as salbutamol, terbutaline, salmeteroland, especially, formoterol and pharmaceutically acceptable saltsthereof, and compounds (in free or salt or solvate form) of formula I ofPCT International Publication No. WO 00/75114, which document isincorporated herein by reference, preferably compounds of the Examplesthereof, especially a compound of formula

in free or pharmaceutically acceptable salt or solvate form.

Combinations of the compound of formula I in crystal form A or B andbeta-2 agonists, PDE4 inhibitors or LTD4 antagonists may be used, forexample, in the treatment of COPD or, particularly, asthma.

Combinations of the compound of formula I in crystal form A or B andanticholinergic or antimuscarinic agents, PDE4 inhibitors, LTB4antagonists may be used, for example, in the treatment of asthma or,particularly, COPD.

In accordance with the foregoing, the invention also provides a methodfor the treatment of an inflammatory condition, particularly aninflammatory or obstructive airways disease, which comprisesadministering to a subject, particularly a human subject, in needthereof an effective amount of the compound of formula I in crystal formA or B as hereinbefore described. In another aspect the inventionprovides the use of the compound of formula I in crystal form A or B forthe manufacture of a medicament for the treatment of an inflammatorycondition, particularly an inflammatory or obstructive airways disease.

The compound of formula I in crystal form A or B may be administered byany appropriate route, e.g. orally, for example in the form of a tabletor capsule; parenterally, for example intravenously; by inhalation, forexample in the treatment of inflammatory or obstructive airways disease;intranasally, for example in the treatment of allergic rhinitis;topically to the skin, for example in the treatment of atopicdermatitis; or rectally, for example in the treatment of inflammatorybowel disease.

In a further aspect, the invention also provides a pharmaceuticalcomposition comprising as active ingredient the compound of formula I incrystal form A or B optionally together with a pharmaceuticallyacceptable diluent or carrier therefor. The composition may contain aco-therapeutic agent such as a bronchodilatory or anti-inflammatory drugas hereinbefore described. Such compositions may be prepared usingconventional diluents or excipients and techniques known in the galenicart. Thus oral dosage forms may include tablets and capsules.Formulations for topical administration may take the form of creams,ointments, gels or transdermal delivery systems, e.g. patches.Compositions for inhalation may comprise aerosol or other atomizableformulations or dry powder formulations.

When the composition comprises an aerosol formulation, it preferablycontains, for example, a hydro-fluoro-alkane (HFA) propellant such asHFA134a or HFA227 or a mixture of these, and may contain one or moreco-solvents known in the art such as ethanol (up to 20% by weight),and/or one or more surfactants such as oleic acid or sorbitan trioleate,and/or one or more bulking agents such as lactose. When the compositioncomprises a dry powder formulation, it preferably contains, for example,the compound of formula I in crystal form A or B having a particlediameter up to 10 microns, optionally together with a diluent orcarrier, such as lactose, of the desired particle size distribution anda compound that helps to protect against product performancedeterioration due to moisture. When the composition comprises anebulised formulation, it preferably contains, for example, the compoundof formula I in crystal form A or B either dissolved, or suspended, in avehicle containing water, a co-solvent such as ethanol or propyleneglycol and a stabiliser, which may be a surfactant.

The invention includes (A) the compound of formula I in crystal form Aor B in inhalable form, e.g. in an aerosol or other atomisablecomposition or in inhalable particulate, e.g. micronised, form, (B) aninhalable medicament comprising the compound of formula I in crystalform A or B in inhalable form; (C) a pharmaceutical product comprisingthe compound of formula I in crystal form A or B in inhalable form inassociation with an inhalation device; and (D) an inhalation devicecontaining the compound of formula I in crystal form A or B in inhalableform.

Dosages of the compound of formula I in crystal form A or B employed inpractising the present invention will of course vary depending, forexample, on the particular condition to be treated, the effect desiredand the mode of administration. In general, suitable daily dosages foradministration by inhalation are of the order of 0.005 to 10 mg, whilefor oral administration suitable daily doses are of the order of 0.05 to100 mg.

The invention is illustrated by the following Examples.

EXAMPLE 1

Preparation and Characterisation of Crystal Form A

50 mg of the compound of formula I is equilibrated in 1 ml isopropanolover 24 hours at 25° C. The product is filtered and dried. After dryingthe compound of formula I is obtained in the form of white crystals.

Measurements are made by X-ray powder diffraction and using Cu—Kα₁. TheX-ray diffraction pattern thus determined, as represented by thereflection lines and intensities of the most important lines, is shownin FIG. 1 and characterised in Table 1 below.

TABLE 1 X-ray diffraction lines and intensities for crystal form A 2θIntensity 3.6 medium 7.3 strong 13.4 medium 14.6 strong 18.3 medium 22.0medium 25.8 strong 25.9 medium 29.5 medium

EXAMPLE 2

Preparation and Characterisation of Crystal Form B

87 mg of the compound of formula I are equilibrated in 2 ml ethanol over24 hours at 25° C. The product is filtered and dried. After drying thecompound of formula I is obtained in the form of white crystals.

Measurements are made by X-ray powder diffraction and using Cu-Kα₁. TheX-ray diffraction pattern thus determined, as represented by thereflection lines and intensities of the most important lines, is shownin FIG. 2 and characterised in Table 2 below.

TABLE 2 X-ray diffraction lines and intensities for crystal form B 2θIntensity 7.2 strong 9.3 Medium 12.0 Medium 12.8 Medium 13.1 Medium 14.5Strong 17.4 Medium 20.4 Medium 23.2 Medium 25.8 Medium

EXAMPLE 3

Preparation of Crystal Forms A and B in Various Solvents

8 mg of the compound of formula I are equilibrated with 1.5 ml of avariety of solvents for at least 24 hours in a water bath at 25° C.±0.1.The solutions are filtered and dried for 10 minutes in the air. Thesolid part is investigated by X-ray powder diffraction (XRPD) toidentify the crystal form produced. The results are shown in Table 3below.

The procedure is repeated at 50° C.±0.1 and 70° C.±0.1 and the resultsare shown in Tables 4 and 5 respectively.

TABLE 3 Equilibration with solvent at 25° C. Solvent XRPD n-ButanolCrystal form A Ethanol Crystal form B Ethyl acetate Crystal form AIsopropanol Crystal form A Hexane Crystal form A Heptane Crystal form AMethanol Crystal form B Methylene chloride Crystal form BTert-butylmethylether Crystal form A Toluene Crystal form ATetrahydrofuran Crystal form A Water Crystal forms A + B

TABLE 4 Equilibration with solvent at 50° C. Solvent XRPD n-ButanolCrystal form A Ethanol Crystal form B Ethyl acetate Crystal form AIsopropanol Crystal form A Hexane Crystal form A Heptane Crystal form AMethanol Crystal form B Methylene chloride Crystal form BTert-butylmethylether Crystal form A Tetrahydrofuran Crystal form AToluene Crystal form A Water Crystal forms A + B

TABLE 5 Equilibration with solvent at 70° C. Solvent XRPD n-ButanolCrystal form A Ethanol Crystal form B Isopropanol Crystal form A

These results show that the choice of solvent dictates which crystalform of the compound of formula I is formed.

EXAMPLE 4

Stability of Crystal Forms A and B

Samples of the compound of formula I in crystal form A, the compound offormula I in crystal form B, a mixture of both crystal forms and anamorphous form of the compound of formula I (obtained by spray drying)are stored for 4 weeks at 80° C. under different conditions and analyzedby X-ray powder diffraction (XRPD). The results are shown in Table 6below.

TABLE 6 Stability after 4 weeks at 80° C. 75% r.h.* N₂ + 2% ConditionsSealed open N₂ water O₂ Crystal form A A A A A A Crystal form B B A + BB A + B A + B Crystal forms A + B A + B A + B A + B A + B A + BAmorphous form A A A A A *relative humidity

These results show that crystal form B can convert at least partially inthe solid state into crystal form A when stored for 4 weeks at 80° C.The amorphous form can also convert into crystal form A. This suggestscrystal form A is more thermodynamically stable than crystal form B.

EXAMPLE 5

Heat of Solution Experiments

The heat of solution of samples of crystal forms A and B of the compoundof formula I are measured at 25° C. in acetone. The results are shown inTable 7 below.

TABLE 7 Heat of solution at 25° C. in acetone Crystal form Heat ofsolution (J/g) A 29.3 B 17.9

These results show crystal form A has a higher endothermic heat ofsolution compared with crystal form B. This indicates crystal form A ismore thermodynamically stable than crystal form B.

1. A compound of formula I

in a crystal form B that has a melting point, by Differential ScanningCalorimetry, of about 270° C. with simultaneous decomposition, at aheating rate of 20° C./min and the following characteristic diffractionlines (2θ in angular degrees±0.2°) in the X-ray diffraction patternthereof: 7.2°, 9.3°, 12.0°, 12.8°, 13.1°, 14.5°, 17.4°, 20.4°, 23.2° and25.8°.
 2. A pharmaceutical composition comprising, as active ingredient,an effective amount of the compound of formula I in crystal form B asdefined in claim 1, optionally together with a pharmaceuticallyacceptable carrier.
 3. A composition according to claim 2, which is ininhalable form.
 4. A pharmaceutical composition comprising a compound offormula I as defined in claim 1 in combination with another drugsubstance which is an anti-inflammatory or a bronchodilator.
 5. Acomposition according to claim 4 wherein the another drug substance is abeta-2 adrenoceptor agonist.
 6. A composition according to claim 5wherein the beta-2 adrenoceptor agonist is selected from the groupconsisting of salbutamol, terbutaline, salmeterol, formoterol and thecompound of formula

in free or pharmaceutically acceptable salt form.
 7. A method oftreating an inflammatory or obstructive airways disease in a subject inneed of such treatment, which comprises administering to said subject aneffective amount of a compound according to claim 1 in crystal form B asdefined in claim
 1. 8. A method of treating asthma or chronicobstructive pulmonary disease in a subject in need of such treatment,which comprises administering to said subject an effective amount of acompound according to claim 1 in crystal form B as defined in claim 1.9. A method of treating atopic dermatitis in a subject in need of suchtreatment, which comprises administering to said subject an effectiveamount of a compound according to claim 1 in crystal form B as definedin claim
 1. 10. A method of preparing a compound of formula I in crystalform B as defined in claim 1 which comprises crystallising the compoundof formula I as defined in claim 1 from a solution thereof in ethanol,methanol or methylene chloride.